Remove support for the unstable identifier from MSC3288. (#515)

changelog.d/515.misc

@@ -0,0 +1 @@
+Remove support for the unstable identifier from [MSC3288](https://github.com/matrix-org/matrix-doc/pull/3288).

docs/templates.md

@@ -110,7 +110,6 @@ Variable                | Contents
 `bracketed_room_name`   | The string stored in `room_name` with brackets around it
 `bracketed_verified_sender`      | The string stored in `sender` with brackets around it
 `medium`                | The string "email"
-`org.matrix.msc3288.room_type`   | **UNSTABLE.** The same as `room_type`
 `org.matrix.web_client_location` | **UNSTABLE.** The same as `web_client_location`
 `room_alias`            | An alias for the room (probably more readable than `room_id`)
 `room_avatar_url`       | The URL of the room's avatar

sydent/http/servlets/store_invite_servlet.py

@@ -122,17 +122,11 @@ def render_POST(self, request: Request) -> JsonDict:
             "sender_avatar_url",
             "guest_user_id",
             "guest_access_token",
+            "room_type",
         ]
         for k in extra_substitutions:
             substitutions.setdefault(k, "")
 
-        # For MSC3288 room type, prefer the stable field, but fallback to the
-        # unstable field.
-        if "room_type" not in substitutions:
-            substitutions["room_type"] = substitutions.get(
-                "org.matrix.msc3288.room_type", ""
-            )
-
         substitutions["bracketed_verified_sender"] = ""
         if verified_sender:
             substitutions["bracketed_verified_sender"] = "(%s) " % (verified_sender,)